When it comes to weed control advice, the phrase “start clean, stay clean” is a great guidepost. However, recent drought-like conditions in the Corn Belt have exposed fields to another threat: herbicide carryover. Bob Berkevich, Pioneer Field Agronomist, has some insights your audience can use when considering how PPO herbicides may affect next season’s crops.
Herbicide carryover can injure crops planted the following year. The concentration of herbicide remaining in the soil at next season’s planting may be too high if dry conditions persist. This will depend on herbicide chemical properties, soil characteristics and the weather.
Additionally, while this season’s crop may be well-suited to tolerating the herbicide used, a rotational crop may be susceptible to injury. Emerging plants are more likely to show injury to residual levels of herbicide if other stressors, such as compaction or cold, wet soils are also present.
Farmers cannot do much to change the concentration of herbicides present in the soil. But there are several steps they can take to help reduce the risk of carryover injury, such reviewing spray records for each field to see what restrictions are indicated or even going so far as delaying planting.